How to replicate UE4 material in Blender?
If you are using the Cycles Renderer, it's practically node-for-node, with slightly different names.  I assumed "Lightness" was a texture:



Note that the grayscale/normal map images should be set to "Non-Color Data" so Blender doesn't gamma-correct them.  You might even want that for the colored image in the lower left. 

I also didn't know what the empty Lerp would do exactly.  You might need to change the colors on that to black (0,0,0) and pure white (1,1,1) to duplicate an empty lerp node. 

If you are trying to use Blender Render, then I don't know if this is possible.